- Preparation and separation properties of oxalylurea-bridged silica membranes
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Two new bridged alkoxysilanes, bis(triethoxysilylalkyl)-N,N′-oxalylureas (alkyl = methyl or n-propyl), bearing a highly rigid and polar oxalylurea unit in the bridges, were employed as precursors of bridged silica membranes. The gas and water separation performance of the membranes prepared from the precursors using the sol-gel process was investigated. Interestingly, the membrane properties depended on the alkyl chain length. The membrane containing methylene units (alkyl = methyl) was porous and rather hydrophilic but the other with longer propylene units (alkyl = n-propyl) was non-porous and more hydrophobic. High H2/SF6 gas permeance ratios of 3100 and 1700, and NaCl rejections of 89 and 85% for 2000 ppm aqueous NaCl were obtained using the membranes containing methyl and n-propyl, respectively. The membrane with alkyl = methyl also showed a high CO2/N2 permeance ratio of 20.6 at 50°C. These results indicate the potential applications of the membranes as gas and water separation materials.
- Mizumo, Tomonobu,Muragishi, Haruna,Yamamoto, Kazuki,Ohshita, Joji,Kanezashi, Masakoto,Tsuru, Toshinori
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- Synthesis of large-pore urea-bridged periodic mesoporous organosilicas
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In this article we report the successful synthesis of a new class of periodic mesoporous organosilicas (PMOs) with a urea-bridged organosilica precursor under acid-catalyzed and inorganic-salt-assisted conditions. The large-pore hybrid materials have an o
- Gao, Ling,Wei, Feng,Zhou, Yu,Fan, Xiao Xing,Wang, Ying,Zhu, Jian Hua
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- Robust urethane-bridged silica aerogels available for water-carved aerosculptures
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Molecular bridged silica aerogels have received extensive interest in recent years due to their easily controlled mechanical properties varying with different organosilane precursors, and without any further post-modification. In this work, a series of novel and robust molecular bridged silica aerogels were prepared by using a symmetrical urethane-bridged monomer, named N,N-bis(propyltriethoxysilyl)carbamide (bPTSCA), which was synthesized via a solvent-free exothermic reaction between 3-isocyanatopropyltriethoxysilane (IPTES) and 3-aminopropyltriethoxysilane (APTES) for several minutes at normal temperature and pressure. The influence of catalysts on the obtained gels and aerogels was studied in detail. It was found that NH4F aqueous solution showed the most effective catalysis capability, and the corresponding aerogels were intact with slight shrinkages. The mechanical strength of these aerogels could reach as high as 100 times more than that of the native silica aerogels (unbridged), and the strength could be easily adjusted from a rigid region to an elastic region simply by varying the sample density. Moreover, these aerogels possessed an interesting character of regional shrinking when encountering with water, which made it possible to fabricate artistic aerosculptures with water or other polar solvents as a graver.
- Zhang, Yulu,Wang, Jin,Wei, Yong,Zhang, Xuetong
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- SILANE COMPOUND, INSULATION LAYER ETCHANT COMPOSITION COMPRISING THE SAME AND METHOD OF FORMING PATTERN USING THE SAME
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Embodiments of the present invention provide a silane compound having a specific structure, an etchant composition comprising the same, and a pattern forming method using the same. The silane compound having the specific structure according to embodiments of the present invention can be water-soluble to suppress gelation or aggregation when added to an aqueous solution.COPYRIGHT KIPO 2020
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Paragraph 0148-0153
(2019/12/25)
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- New silatranes possessing urea functionality: Synthesis, characterization and their structural aspects
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The present work aims at the synthesis of various novel silatranes bearing substituted urea functionality. Nucleophilic addition of various amines (morpholine, aniline, ethylenediamine and 3-aminopropyltriethoxysilane) to 3-isocyanatopropyltriethoxysilane
- Puri, Jugal Kishore,Singh, Raghubir,Chahal, Varinder Kaur,Sharma, Raj Pal,Wagler, J?rg,Kroke, Edwin
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experimental part
p. 1341 - 1348
(2011/05/09)
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